In a constant-voltage DC circuit, if the resistance value increases while the supply voltage remains unchanged, what happens to the circuit current according to Ohm's law?

Introduction:
Ohm's law is the foundational relationship linking voltage, current, and resistance in DC circuits. This question checks whether you can qualitatively predict how current changes when resistance changes while the applied voltage is kept constant.

Given Data / Assumptions:

• Ideal DC source with fixed voltage (constant V).
• Single effective resistance R in the path of current.
• Temperature and other secondary effects are neglected so R is constant except for the stated change.

Concept / Approach:
Ohm's law states I = V / R. With V fixed, current I is inversely proportional to R. Therefore, if R increases, the denominator grows and I must decrease in direct proportion. This inverse relationship underpins many circuit design decisions, such as selecting resistors to set bias currents or limiting current to safe values.

Step-by-Step Solution:
1) Start from Ohm's law: I = V / R.2) Treat V as a constant because the source is fixed.3) Increase R to a higher value R'.4) Since the denominator increased, the fraction V / R' is smaller than V / R.5) Therefore, the current decreases when resistance increases at constant voltage.

Verification / Alternative check:
Use a numeric example: if V = 10 V and R changes from 100 Ω to 200 Ω, current changes from 0.1 A to 0.05 A. The current halves as the resistance doubles, exactly matching I ∝ 1/R.

Why Other Options Are Wrong:
Increase: contradicts I = V / R when V is constant.
Stay the same: would only occur if R did not change or V changed proportionally.
Not enough information: the law fully determines the outcome with V fixed and R increased.
Oscillate: describes AC or time-varying phenomena, not a DC steady-state relationship.

Common Pitfalls:
Confusing cause and effect (thinking current controls voltage) or forgetting that resistance sets current for a given fixed voltage. Ensure units are consistent and remember the inverse proportionality.

Final Answer:
decrease